The present invention is related to screwdrivers, and more particularly to a screwdriver which is convenient in use for turning screws without stopping, and which can be firmly secured to a screw to be fastened or loosened during the screw turning operation.
A screwdriver is a hand tool for turning screws. During the screw turning operation through a single-piece type of hand-driven screwdriver, the hand-driven screwdriver must be frequently removed from a screw each time the user's wrist is turned to a certain angle. Therefore, a screw can not be continuously turned through a conventional single-piece type of hand-driven screwdriver without a temporary stop.
Further, before the tip of the blade of a hand-driven screwdriver fits into the slotted head of a screw, a screw must be held with the fingers or by an external tool to keep it in position. During driving, it is very difficult to hold a screw in position with the fingers or the external tool. This problem may be overcome by using a screwdriver which has a retainer socket for securing the blade of the screwdriver to a screw. A disadvantage of this type of screwdriver is that the retainer socket is fixedly latter secured to the blade thereof. For turning screws of different specifications, several screwdrivers with different specifications of retainer sockets may be required.